1. Field of the Invention
This invention relates to aquariums, and more particularly, to decorative assemblies for moving and filtering water from an aquarium over a decorative waterfall surface, and back to the aquarium.
2. Description of the Related Art
Aquariums are popular for several reasons. They provide a fun hobby, are educational, and are relaxing to watch. In addition, some aquariums are highly decorative forms of art. In caring for most aquariums, owners need to control the aquatic environment by filtering and aerating the water, as well as by maintaining water temperature. At the same time, owners want their aquariums to have a decorative and natural appearance. Yet, these two objectives often are inconsistent. Aquarium filtration units and heaters typically detract from an aquarium's appearance, while decorative aquarium displays do not assist in controlling the aquatic environment. For example, aquarium waterfalls are described in the art as a way of enhancing an aquarium's appearance. However, these waterfall systems do not maintain the quality of the water, and therefore, conventional heating and filtering units must still be used. Furthermore, these waterfalls have limited utility as decorative devices because of their design, as seen in the following patents.
U.S. Pat. No. 3,057,094 to Winkelman teaches a self-contained underwater waterfall in an aquarium. The self-contained system includes water and sand, as well as an air inlet. As air is pumped into the contained system, the water-sand-air mixture moves up a tube and then down the enclosed waterfall. The sand is added to the waterfall system so that one may see the waterfall flowing. Because the waterfall is underneath the water surface in the aquarium tank, one cannot hear the flow of the water. In addition, it may be difficult to see the flow of water down the spillway. Furthermore, the waterfall serves only a decorative purpose, and does not help in aerating or filtering the aquarium water.
Wininger U.S. Pat. No. 3,390,655 discloses an apparatus simulating a waterfall under water in an aquarium tank. The simulated waterfall includes an air tube, an uptake tube and an outlet tube. Air is pumped from the air tube to the uptake tube, drawing sand and water from the aquarium bottom into the uptake tube. As this sand and water reaches the top of the uptake tube, the sand-water mixture moves through the outflow tube and back into the main body of the aquarium. Because the simulated waterfall is under water, sand must be used in order to see the simulated flow. The waterfall is simulated because only the sand trickles down from the outflow tube to the base of the tank. The water exiting the outflow tube has the same density as the remainder of the water in the tank, and therefore it does not trickle or flow down the waterfall surface to the base of the tank. Also since the simulated waterfall is under water, an observer does not have the enjoyment of hearing the waterfall.
In U.S. Pat. No. 4,836,142, Duback teaches a multiple tank aquarium system in which water flows from one tank over a spillway into the top of another tank having a lower water line. The water is pumped from the tank having the lowest water line back into the tank having the highest water line. Because the flow of water takes place above the water surface of the tank having the lower water line, an observer may enjoy the sound of water rushing over the spillway. However, the system requires multiple tanks and does not include a decorative waterfall surface. In addition, although the system aerates the water, it provides no filtration.